/*
 * Copyright 2012-2021 the original author or authors.
 * Copy from spring-boot-loader
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.gitee.starblues.loader.jar;

import com.gitee.starblues.loader.utils.IOUtils;

import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.ref.WeakReference;
import java.net.MalformedURLException;
import java.net.URL;
import java.security.Permission;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.jar.Manifest;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import java.util.zip.ZipEntry;

import com.gitee.starblues.loader.utils.ObjectUtils;

/**
 * A wrapper used to create a copy of a {@link JarFile} so that it can be safely closed
 * without closing the original.
 *
 * @author Phillip Webb
 */
public class JarFileWrapper extends JarFile {

    private final String parentName;

    private final JarFile parent;
    private final ConcurrentHashMap<String, ConcurrentLinkedQueue<WeakReference<InputStream>>> inputStreamCache;

    private final AtomicBoolean canClosed = new AtomicBoolean(false);

    JarFileWrapper(JarFile parent) throws IOException {
        super(parent.getRootJarFile().getFile());
        this.parent = parent;
        this.parentName = "JarWrapper-" + System.identityHashCode(this) + "-For-" + parent.getName();
        this.inputStreamCache = new ConcurrentHashMap<>();
    }

    @Override
    public URL getUrl() throws MalformedURLException {
        return this.parent.getUrl();
    }

    @Override
    JarFileType getType() {
        return this.parent.getType();
    }

    @Override
    Permission getPermission() {
        return this.parent.getPermission();
    }

    @Override
    public Manifest getManifest() throws IOException {
        return this.parent.getManifest();
    }

    @Override
    public Enumeration<java.util.jar.JarEntry> entries() {
        return this.parent.entries();
    }

    @Override
    public Stream<java.util.jar.JarEntry> stream() {
        return this.parent.stream();
    }

    @Override
    public com.gitee.starblues.loader.jar.JarEntry getJarEntry(String name) {
        return this.parent.getJarEntry(name);
    }

    @Override
    public ZipEntry getEntry(String name) {
        return this.parent.getEntry(name);
    }

    @Override
    InputStream getInputStream() throws IOException {
        InputStream inputStream = new TrackedInputStream(parentName, this.parent.getInputStream());
        addInputStream(parentName, inputStream);
        return inputStream;
    }

    @Override
    public InputStream getInputStream(ZipEntry ze) throws IOException {
        InputStream inputStream = new TrackedInputStream(ze.getName(), this.parent.getInputStream(ze));
        addInputStream(ze.getName(), inputStream);
        return inputStream;
    }

    private class TrackedInputStream extends FilterInputStream {
        private final String entryName;
        private volatile boolean closed = false;

        TrackedInputStream(String entryName, InputStream in) {
            super(in);
            this.entryName = entryName;
        }

        @Override
        public void close() throws IOException {
            if (!closed) {
                closed = true;
                super.close();
                // 从缓存中移除（如果需要缓存的话）
                removeFromCache(entryName, this);
            }
        }
    }

    @Override
    public String getComment() {
        return this.parent.getComment();
    }

    @Override
    public int size() {
        return this.parent.size();
    }

    @Override
    public String toString() {
        return this.parent.toString();
    }

    @Override
    public String getName() {
        return this.parent.getName();
    }

    @Override
    public void close() throws IOException {
        // Modified Added close logic
        if (canClosed.get()) {
            closeAllTrackedStreams();
            inputStreamCache.clear();
            IOUtils.closeQuietly(parent);
        }
    }

    public void canClosed() {
        canClosed.set(true);
    }

    private void addInputStream(String name, InputStream inputStream) {
        inputStreamCache.compute(name, (key, queue) -> {
            if (queue == null) {
                queue = new ConcurrentLinkedQueue<>();
            }
            // 定期清理已GC的引用（每添加10次清理一次）
            if (queue.size() % 10 == 0) {
                queue.removeIf(ref -> ref.get() == null);
            }
            queue.add(new WeakReference<>(inputStream));
            return queue;
        });
    }

    private void removeFromCache(String name, TrackedInputStream trackedInputStream) throws IOException {
        inputStreamCache.computeIfPresent(name, (key, queue) -> {
            // 移除匹配的引用和已GC的引用
            queue.removeIf(ref -> {
                InputStream stream = ref.get();
                return stream == null || stream == trackedInputStream;
            });
            return queue.isEmpty() ? null : queue;
        });
    }

    private void closeAllTrackedStreams() {
        for (ConcurrentLinkedQueue<WeakReference<InputStream>> queue : inputStreamCache.values()) {
            if (queue != null) {
                for (WeakReference<InputStream> ref : queue) {
                    InputStream stream = ref.get();
                    if (stream != null) {
                        IOUtils.closeQuietly(stream);
                    }
                }
            }
        }
    }

    static JarFile unwrap(java.util.jar.JarFile jarFile) {
        if (jarFile instanceof JarFile) {
            return (JarFile) jarFile;
        }
        if (jarFile instanceof JarFileWrapper) {
            return unwrap(((JarFileWrapper) jarFile).parent);
        }
        throw new IllegalStateException("Not a JarFile or Wrapper");
    }

}

